package main

import "fmt"

func main() {
	callback(4, Add)
}

func Add(a, b int) {
	fmt.Printf("the sum of %d and %d is : %d \n ", a, b, a+b)
}

func callback(y int, f func(int, int)) {
	// 2作为固定删除
	f(y, 2)
}
